Background: Research-grade pancreata preserved by the two-layer method (TLM) compared to organs stored with University of Wisconsin (UW) solution prior to islet isolation result in significantly better islet yields. However, it is unknown whether the TLM improves islet yields from pancreata that meet the criteria for the selection of clinical-grade organs.
Methods: Six clinical-grade pancreata were preserved for 4.8 +/- 0.5 hour in UW and three clinical-grade pancreata were preserved by the TLM for 11.7 +/- 2.0 hour. The local team procured all pancreata. All donors were hemodynamically stable without norepinephrine usage and length of hospitalization was less than 96 hour. Causes of death were either head trauma or cerebrovascular accident. Islets were isolated and evaluated according to the Edmonton protocol.
Results: The TLM as compared to UW resulted in a significant increase in islet yields (3415 +/- 227 vs 2006 +/- 337 IE/g pancreas, P <.03). The quality of islets as assessed by visual score was significantly better in the TLM group (8.7 +/- 0.2 vs 7.3 +/- 0.3, P <.02) but other parameters (viability, survival rate after culture, insulin content, stimulation index) were similar between the two groups. We transplanted all three islet preparations in the TLM group but only two of six preparations from the UW group.
Conclusion: Compared to UW, exposure of pancreata to the TLM resulted in greater islet yields and extended preservation times with clinical grade pancreas. Pancreata should be preserved by the TLM prior to islet isolation even for donors that meet clinical grade organ selection criteria. The Human Islet Transplantation in Seattle (HITS) Consortium is supported in part by a grant from the Juvenile Diabetes Research Foundation International. The HITS consortium is an islet transplant program involving the University of Washington, Pacific Northwest Research Institute, the Puget Sound Blood Center, Fred Hutchinson Cancer Research Center, Swedish Hospital, and the Virginia Mason Research Center.